Flame-retardant silicone sealant and preparation method thereof

Abstract

The invention relates to a flame-retardant silicone sealant and a preparation method thereof, and in particular relates to a flame-retardant silicone sealant which is characterized by comprising the following components in parts by weight: alpha, alpha, beta, beta, beta, beta, beta-tetramethyl-1, 3-pentanediol monoisobutyrate, the invention discloses a flame-retardant silicone rubber, which comprises the following components in parts by weight: 100 parts of alpha, omega-dihydroxy polydimethylsiloxane, 30-50 parts of methyl phenyl silicone oil, 160-200 parts of filler, 20-50 parts of a cross-linking agent curing agent, 2-5 parts of a cross-linking agent, 1-4 parts of a coupling agent, 1-3 parts of a catalyst tetraisopropyl titanate and 25-50 parts of a flame retardant, wherein the cross-linking agent is prepared by mixing 3-amino-5-methylpyridine and 3-chloropropyltrimethylsilane according to a molar ratio of 1: 2.1.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a flame retardant silicone sealant and a preparation method thereof. Background Art

[0002] With the widespread application of renewable energy, solar photovoltaic systems have become a green, efficient and sustainable energy solution. The manufacturing, packaging and installation of silicon wafers in photovoltaic modules are one of the key links. As an important encapsulation adhesive, silicone adhesive is often used in the manufacturing and installation of solar photovoltaic modules. The application environment of adhesive for solar photovoltaic modules is mainly outdoor, which puts forward the following performance requirements for its performance: good weather resistance, able to withstand severe cold, heat, strong winds and rainstorms; fast curing, easy to carry; flame retardant effect. Therefore, there is still a need to develop new flame retardant silicone sealants. Summary of the invention

[0003] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a flame retardant silicone sealant and a preparation method thereof.

[0004] To achieve the purpose of the present invention, on the one hand, the present invention provides a flame retardant silicone sealant, which includes, by weight: 100 parts of α, ω-dihydroxy polydimethylsiloxane, 30-50 parts of methylphenyl silicone oil, 160-200 parts of filler, 20-50 parts of crosslinking agent curing agent, 2-5 parts of crosslinking agent, 1-4 parts of coupling agent, 1-3 parts of catalyst tetraisopropyl titanate, and 25-50 parts of flame retardant, wherein the crosslinking agent is prepared by mixing 3-amino-5-methylpyridine and 3-chloropropyltrimethylsilane in a molar ratio of 1:2.1.

[0005] In some preferred embodiments, the filler of the present invention is selected from one or more of active sodium calcium carbonate, ultrafine light calcium carbonate, silicon powder, quartz powder, talcum powder and mica powder. Preferably, the filler is active sodium calcium carbonate.

[0006] In some preferred embodiments, the cross-linking curing agent of the present invention is prepared by mixing vinyl tributylidene oxime siloxane and tetraethyl orthosilicate in a mass ratio of 1: (10-30).

[0007] In some preferred embodiments, the coupling agent of the present invention is prepared by mixing bisaminosilane oligomer and aminoethylaminopropyltrimethoxysilane in a mass ratio of (2-4):1.

[0008] In some preferred embodiments, the flame retardant of the present invention is selected from at least one of magnesium hydroxide and magnesium oxide.

[0009] In some preferred embodiments, the present invention provides a flame retardant silicone sealant, which includes, by weight: 100 parts of α, ω-dihydroxy polydimethylsiloxane, 35-45 parts of methylphenyl silicone oil, 170-190 parts of filler, 30-40 parts of crosslinking agent curing agent, 3-4 parts of crosslinking agent, 2-3 parts of coupling agent, 2-3 parts of catalyst tetraisopropyl titanate, and 30-40 parts of flame retardant, wherein the crosslinking agent is prepared by mixing 3-amino-5-methylpyridine and 3-chloropropyltrimethylsilane in a molar ratio of 1:2.1.

[0010] In some preferred embodiments, the present invention provides a flame retardant silicone sealant, which includes, by weight: 100 parts of α, ω-dihydroxy polydimethylsiloxane, 35-40 parts of methylphenyl silicone oil, 175-185 parts of filler, 35-40 parts of crosslinking agent curing agent, 3-4 parts of crosslinking agent, 2-3 parts of coupling agent, 2-3 parts of catalyst tetraisopropyl titanate, and 35-40 parts of flame retardant, wherein the crosslinking agent is prepared by mixing 3-amino-5-methylpyridine and 3-chloropropyltrimethylsilane in a molar ratio of 1:2.1.

[0011] In some preferred embodiments, the present invention provides a flame retardant silicone sealant, which includes, by weight: 100 parts of α, ω-dihydroxy polydimethylsiloxane, 40 parts of methylphenyl silicone oil, 180 parts of filler, 35 parts of crosslinking agent curing agent, 4 parts of crosslinking agent, 3 parts of coupling agent, 2 parts of catalyst tetraisopropyl titanate, and 40 parts of flame retardant, wherein the crosslinking agent is prepared by mixing 3-amino-5-methylpyridine and 3-chloropropyltrimethylsilane in a molar ratio of 1:2.1.

[0012] The present invention also provides a method for preparing a flame retardant silicone sealant, comprising:

[0013] 1) Weighing α,ω-dihydroxy polydimethylsiloxane, methylphenyl silicone oil, filler, crosslinking agent curing agent, crosslinking agent, coupling agent, flame retardant and catalyst tetraisopropyl titanate according to the above weight percentages;

[0014] 2) Mix α,ω-dihydroxypolydimethylsiloxane, methylphenyl silicone oil, filler and flame retardant evenly, add crosslinking agent, curing agent and crosslinking agent after cooling, mix evenly, evacuate, add catalyst and coupling agent under vacuum degree of 0.07-0.10MPa, mix evenly, and obtain the silicone glue.

[0015] Preferably, the cooling temperature in step 2) is 50-60°C.

[0016] The present invention also provides a method for preparing a cross-linking agent, which comprises the following reaction steps: firstly placing 3-amino-5-methylpyridine into a reaction bottle under stirring conditions, and then dropwise adding 2.1 molar equivalents of 3-chloropropyltrimethylsilane into the 3-amino-5-methylpyridine under nitrogen protection.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) The present application designs and prepares a cross-linking agent with a novel structure, which cooperates with the cross-linking agent curing agent to achieve a balanced reaction activity of the entire system through the synergistic effect with the preferred components and dosages in the system, thereby shortening the curing time and achieving excellent bonding strength;

[0019] 2) The coupling agent is prepared by mixing bisaminosilane oligomer and aminoethylaminopropyltrimethoxysilane in a mass ratio of (2-4):1. The use of the two to each other improves the situation that a single coupling agent does not adhere to individual substrates, can expand the application scope of bonding and greatly improve the bonding effect;

[0020] 3) The present invention adds flame retardant to enhance the flame retardant effect. DETAILED DESCRIPTION

[0021] The following representative examples are intended to better illustrate the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the materials used in the following examples were commercially available.

[0022] α,ω-dihydroxypolydimethylsiloxane was purchased from Tianjin Xiensi Biochemical Technology Co., Ltd.;

[0023] Methylphenyl silicone oil was purchased from Shandong West Asia Chemical Co., Ltd.;

[0024] Active sodium calcium carbonate was purchased from Shanghai Daewoo Biochemical Co., Ltd.

[0025] Preparation Example Preparation of cross-linking agent

[0026] Under stirring conditions, 10 mol of 3-amino-5-methylpyridine was first placed in a reaction bottle, and under nitrogen protection, 21 mol of 3-chloropropyltrimethylsilane was added dropwise to the 3-amino-5-methylpyridine, and the addition was completed within 4 hours; the stirring speed was maintained at 60 rpm, and the reaction was carried out at 50° C. for 5 hours to obtain the cross-linking agent.

[0027] Example 1

[0028] Weigh 100 parts of α,ω-dihydroxy polydimethylsiloxane, 40 parts of methylphenyl silicone oil, 180 parts of active sodium calcium carbonate, 35 parts of a crosslinking agent and curing agent (vinyl trisbutyl ketoxime siloxane and ethyl orthosilicate mixed in a mass ratio of 1:20), 4 parts of a crosslinking agent prepared in the preparation example, 3 parts of a coupling agent (bisaminosilane oligomer and aminoethylaminopropyltrimethoxysilane mixed in a mass ratio of 3:1), 2 parts of a catalyst tetraisopropyl titanate, and 40 parts of a flame retardant according to weight percentage; mix the α,ω-dihydroxy polydimethylsiloxane, methylphenyl silicone oil, active sodium calcium carbonate, and flame retardant evenly, add the crosslinking agent and curing agent and the crosslinking agent after cooling, mix evenly, evacuate, add the catalyst and the coupling agent under a vacuum degree of 0.08 MPa, mix evenly, and obtain the silicone glue.

[0029] Example 2

[0030] Weigh 100 parts of α,ω-dihydroxy polydimethylsiloxane, 35 parts of methylphenyl silicone oil, 175 parts of silicon powder, 30 parts of crosslinking agent curing agent (vinyl trisbutyl ketoxime siloxane and ethyl orthosilicate mixed in a mass ratio of 1:20), 3 parts of the crosslinking agent prepared in the preparation example, 3 parts of coupling agent (bisaminosilane oligomer and aminoethylaminopropyltrimethoxysilane mixed in a mass ratio of 3:1), 2 parts of catalyst tetraisopropyl titanate, and 35 parts of flame retardant according to weight percentage; mix α,ω-dihydroxy polydimethylsiloxane, methylphenyl silicone oil, quartz powder, and flame retardant evenly, add crosslinking agent curing agent and crosslinking agent after cooling, mix evenly, evacuate, add catalyst and coupling agent under vacuum degree of 0.09MPa, mix evenly, and obtain the silicone glue.

[0031] Example 3

[0032] Weigh 100 parts of α,ω-dihydroxy polydimethylsiloxane, 45 parts of methylphenyl silicone oil, 190 parts of talc, 40 parts of a crosslinking agent and curing agent (vinyl trisbutyl ketoxime siloxane and ethyl orthosilicate mixed in a mass ratio of 1:20), 4 parts of a crosslinking agent prepared in the preparation example, 3 parts of a coupling agent (bisaminosilane oligomer and aminoethylaminopropyltrimethoxysilane mixed in a mass ratio of 3:1), 1 part of a catalyst tetraisopropyl titanate, and 30 parts of a flame retardant according to weight percentage; mix the α,ω-dihydroxy polydimethylsiloxane, methylphenyl silicone oil, talc, and flame retardant evenly, add a crosslinking agent and curing agent and a crosslinking agent after cooling, mix evenly, evacuate, add a catalyst and a coupling agent under a vacuum degree of 0.07 MPa, mix evenly, and obtain the silicone glue.

[0033] Example 4

[0034] Weigh 100 parts of α,ω-dihydroxy polydimethylsiloxane, 35 parts of methylphenyl silicone oil, 175 parts of active sodium calcium carbonate, 35 parts of a crosslinking agent curing agent (vinyl trisbutyl ketoxime siloxane and ethyl orthosilicate mixed in a mass ratio of 1:20), 4 parts of a crosslinking agent prepared in the preparation example, 3 parts of a coupling agent (bisaminosilane oligomer and aminoethylaminopropyltrimethoxysilane mixed in a mass ratio of 3:1), 2 parts of a catalyst tetraisopropyl titanate, and 35 parts of a flame retardant according to weight percentage; mix the α,ω-dihydroxy polydimethylsiloxane, methylphenyl silicone oil, active sodium calcium carbonate, and flame retardant evenly, add the crosslinking agent curing agent and the crosslinking agent after cooling, mix evenly, evacuate, add the catalyst and the coupling agent under a vacuum degree of 0.10 MPa, mix evenly, and obtain the silicone glue.

[0035] Comparative Example 1

[0036] Weigh 100 parts of α,ω-dihydroxy polydimethylsiloxane, 35 parts of methylphenyl silicone oil, 175 parts of active sodium calcium carbonate, 35 parts of a crosslinking agent and curing agent (vinyl trisbutyl ketoxime siloxane and ethyl orthosilicate mixed in a mass ratio of 1:40), 1 part of a crosslinking agent prepared in the preparation example, 3 parts of a coupling agent (bisaminosilane oligomer and aminoethylaminopropyltrimethoxysilane mixed in a mass ratio of 6:1), 2 parts of a catalyst tetraisopropyl titanate, and 15 parts of a flame retardant according to weight percentage; mix the α,ω-dihydroxy polydimethylsiloxane, methylphenyl silicone oil, active sodium calcium carbonate, and flame retardant evenly, add the crosslinking agent and curing agent and the crosslinking agent after cooling, mix evenly, evacuate, add the catalyst and the coupling agent under a vacuum degree of 0.05 MPa, mix evenly, and obtain the silicone glue.

[0037] Comparative Example 2

[0038] A fast-curing two-component silicone structural adhesive product was prepared by referring to the preparation method of Example 3 in CN114262599A.

[0039] The flame retardant silicone sealants prepared in the above examples and comparative examples were tested for performance. The limiting oxygen index (LOI) was measured using an oxygen index tester in accordance with GB / T2406-2009. The obtained data are shown in the following table:

[0040] Table 1 Performance test results

[0041]

[0042] Compared with the comparative example, the flame retardant silicone sealant of the present invention has a short curing time, a good flame retardant effect and excellent comprehensive performance.

[0043] Although the present invention has been described in detail above, it is understood by those skilled in the art that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention. The scope of the present invention is not limited to the detailed description above, but should be attributed to the claims.

Claims

1. A flame retardant silicone sealant, It is characterized in that The invention comprises, by weight: 100 parts of α,ω-dihydroxy polydimethylsiloxane, 30-50 parts of methylphenyl silicone oil, 160-200 parts of filler, 20-50 parts of crosslinking agent curing agent, 2-5 parts of crosslinking agent, 1-4 parts of coupling agent, 1-3 parts of catalyst tetraisopropyl titanate, and 25-50 parts of flame retardant, wherein the crosslinking agent is prepared by mixing 3-amino-5-methylpyridine and 3-chloropropyltrimethylsilane in a molar ratio of 1:2.

1.

2. The flame retardant silicone sealant according to claim 1, It is characterized in that The filler is selected from one or more of active sodium calcium carbonate, ultrafine light calcium carbonate, silicon powder, quartz powder, talcum powder and mica powder.

3. The flame retardant silicone sealant according to claim 1, It is characterized in that The cross-linking curing agent is prepared by mixing vinyl tributylidene oxime siloxane and ethyl orthosilicate in a mass ratio of 1: (10-30).

4. The flame retardant silicone sealant according to claim 1, It is characterized in that The coupling agent is prepared by mixing bisaminosilane oligomer and aminoethylaminopropyltrimethoxysilane in a mass ratio of (2-4):

1.

5. The flame retardant silicone sealant according to claim 1, It is characterized in that The flame retardant is selected from at least one of magnesium hydroxide and magnesium oxide.

6. The flame retardant silicone sealant according to claim 1, It is characterized in that The invention comprises, by weight: 100 parts of α,ω-dihydroxy polydimethylsiloxane, 35-45 parts of methylphenyl silicone oil, 170-190 parts of filler, 30-40 parts of crosslinking agent and curing agent, 3-4 parts of crosslinking agent, 2-3 parts of coupling agent, 2-3 parts of catalyst tetraisopropyl titanate, and 30-40 parts of flame retardant, wherein the crosslinking agent is prepared by mixing 3-amino-5-methylpyridine and 3-chloropropyltrimethylsilane in a molar ratio of 1:2.

1.

7. The flame retardant silicone sealant according to claim 1, It is characterized in that In parts by weight, it includes: 100 parts of α,ω-dihydroxypolydimethylsiloxane, 35-40 parts of methylphenyl silicone oil, 175-185 parts of filler, 35-40 parts of crosslinking agent curing agent, 3-4 parts of crosslinking agent, 2-3 parts of coupling agent, 2-3 parts of catalyst tetraisopropyl titanate, and 35-40 parts of flame retardant, wherein the crosslinking agent is prepared by mixing 3-amino-5-methylpyridine and 3-chloropropyltrimethylsilane in a molar ratio of 1:2.

1.

8. The flame retardant silicone sealant according to claim 1, It is characterized in that In parts by weight, it includes: 100 parts of α,ω-dihydroxypolydimethylsiloxane, 40 parts of methylphenyl silicone oil, 180 parts of filler, 35 parts of crosslinking agent curing agent, 4 parts of crosslinking agent, 3 parts of coupling agent, 2 parts of catalyst tetraisopropyl titanate, and 40 parts of flame retardant, wherein the crosslinking agent is prepared by mixing 3-amino-5-methylpyridine and 3-chloropropyltrimethylsilane in a molar ratio of 1:2.

1.

9. A method for preparing a flame retardant silicone sealant, include: 1) Weighing α,ω-dihydroxy polydimethylsiloxane, methylphenyl silicone oil, filler, crosslinking agent curing agent, crosslinking agent, coupling agent, flame retardant and catalyst tetraisopropyl titanate according to the above weight percentages; 2) Mix α,ω-dihydroxypolydimethylsiloxane, methylphenyl silicone oil, filler and flame retardant evenly, add crosslinking agent, curing agent and crosslinking agent after cooling, mix evenly, evacuate, add catalyst and coupling agent under vacuum degree of 0.07-0.10MPa, mix evenly, and obtain the silicone glue.

10. The preparation method according to claim 9, It is characterized in that In step 2), the cooling temperature is 50-60°C.

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